Method of separating a continuous series of knit articles



United States Patent Rudolph H. Wyner, Brookline, mut, Inc., Stoughton, Mass., chusetts Filed Dec. 4, 1958, Ser. No. 778,164

2 Claims. (Cl. 28-72) Mass., assignor to Shawa corporation of Massa- This invention relates to fabric articles knitted as successive portions of a continuous length of fabric and more particularly to a novel method of separating such fabric into individual articles.

In making certain knitted articles, for example knitted collars which are to be separately attached to garments, it has been customary to knit a series of the articles as a continuous piece of fabric, but in accordance with procedures whereby each individual articles is provided with a finished edge.

In knitting a continuous series of articles, the customary practice has been to join the edges of adjacent articles by knitting therebetween a special yarn, commonly called a rave yarn, which can be later removed to separate the pieces without damage to the base fabric. The usual practice in separation has been simply to pull out the ravel yarn thereby disengaging the successive articles. However, this is a separate operation, usually performed by hand, and is difficult to accomplish when the article is of appreciable width. It has also been proposed to make the ravel yarns of suitable synthetic material which can be removed from the fabric by heating until the yarn is melted or by immersing the string fabric in a solvent to dissolve the ravel yarn. These proposals also involve an additional processing step and often necessitate an additional handling where the separated articles collect in a single place.

The principal object of this invention is to provide a method by which a string fabric of knitted articles may be continuously and automatically separated and thereafter fed individually and in series to a receiving station.

In accordance with this invention, a string fabric comprising a series of knitted articles joined together by a fusible ravel yarn (the ravel yarn melting at a temperature below the scorching temperature of the fabric) is separated by passing the string fabric over a perforated surface and passing heated air through said fabric and then through said perforations, the heated air melting the ravel yarns to separate the articles. Preferably the perforated surface is the peripheral surface of a rotating drum, the interior of which is maintained at a pressure below the air pressure external to the drum thereby drawing the heated air through the surface perforations. The heated air, thus moving through the fabric, melts the fusible yarn joining the articles together; holds the separated articles to the surface of the drum; and will dry the fabric if necessary. As the drum rotates, the separated articles are removed, one after another, from the surface of the drum and passed to a conveyor which delivers them in series to a receiving station.

This invention may be better understood by reference to the accompanying drawings wherein:

Fig. 1 is a side view of separating apparatus with parts in section; and

Fig. 2 is a plan view with the cabinet in section.

Referring to the drawing which illustrates apparatus for carrying out the present invention, the numeral 2 designates a string fabric comprising a number of continuously knitted articles 12, 14, 16, etc., each joined to the next by a fusible ravel yarn according to known processes.

A roll 18 of the knitted string fabric 10 is fed onto a conveyor 20 which conveys it through an opening 22 in cabinet 24 and delivers it to a rotating drum 26. As the drum rotates, the fabric 10 is carried around the drum circumference to a take-01f bar 28 which removes the separated articles and deposits them on a conveyor 30, by which they are automatically delivered in a separated condition to any desired receiving station.

The periphery of the drum 26 is a cylindrical shell having perforations 32. One end 34 of the drum 26 is closed, while the opposite end is open and disposed adjacent to a fan 36 turned bymotor 38. As the fan 36 rotates, air is withdrawn from the interior of the drum, thereby reducing the pressure therein as compared with the air pressure at the outside of the drum. To aid in maintaining this reduced pressure, the fan 36 turns within a circular baflie 40 while the open end of the drumturns in a confining baffie'42, thereby providing a restricted chamber 43 communicating with the interior of the drum.

As the fan 36 reduces the pressure in the drum 26, air is drawn downwardly, preferably through a screen 44 at the top of cabinet 24, through an electrical heater 46, of any desired type, disposed above the drum, through the fabric 10 which rests upon the upper portion of the drum, and through the drum perforations 32 to the fan discharge outlet 48. The cabinet is further provided with additional baffles 50 and 52 which prevent entry of air into the lower part of the cabinet and thus restricts the passage of air through the periphery of the drum to that portion which is covered by the fabric 10.

As the heated air is drawn downwardly through the cloth in moving toward the perforations, the cloth will be dried, if moist, and the fusible ravel yarns, joining the several articles together, will be melted and the articles thereby separated. For this purpose, the air is heated to a temperature which is above the melting temperature of the ravel yarn, but which is below the temperature which will scorch or otherwise injure the base fabric. The separated articles will be retained after separation on the surface of the drum by the external air pressure. When the separated articles reach the bar 28, they are separated from the surface of the drum and drop onto the conveyor 30 which preferably moves at a surface speed higher than the surface speed of the drum thereby conveniently separating the individual pieces to any desired extent.

Articles continuously knitted in string formation are, by this method, automatically separated and fed in orderly fashion to any desired receiving station in convenient form for subsequent operations. In one particular example, articles are knitted from cotton and/or wool and joined together during the knitting thereof by an interknitted polyethylene yarn which melts at a temperature of the order of 225 F. The air is heated to a temperature such as to melt the connecting yarn before it contacts the fabric, for example to a temperature of 225 F. or slightly higher, but not high enough to injure the material forming the knitted articles, thereby melting the polyethylene yarn and separating the articles. No difliculty is experienced from the build-up of melted polyethylene on the surface of the drum 26.

While a single rotating drum has been illustrated herein, it is obvious that the string fabric could be fed over additional drums, if desired, to give a longer heating path. Also any equivalent heating or exhausting means can be substituted for the heater 46 or the fan 36.

It should be understood that the embodiment herein described is for the purpose of illustration only and that the invention includes all modifications falling within the scope of the appended claims.

I claim:

l. The method of preparing like knitted articles in which said articles are knitted as successive portions of a strip of fabric and each such portion is connected to the next by an interknitted yarn of a material which melts at a temperature below that which would injure the material of which said articles are formed, comprising as steps supporting the knitted fabric on a porous support, moving said supported fabric along a predetermined path, drawing air through the moving fabric and thereafter through the support, first heating said air to a temperature such as to melt the connecting yarn without injury to the material of which the articles are formed, preserving the relative arrangement of the separated,

knitted articles while on said support, and successively removing the articles from the support.

2. The method according to claim 1, wherein said predetermined path is arcuate and wherein a pressure difference is maintained between the exposed surface of said articles and beneath said support suflicient to hold the separated articles on the surface until removal therefrom.

References Qited in the file of this patent UNITED STATES PATENTS 2,297,881 Fuller Oct. 6, 1942 2,437,735 Getaz Mar. 16, 1948 FOREIGN PATENTS 612,495 Great Britain Nov. 12, 1948 

